Piezo-electric oscillator



May 21, 1929. J F|EGQ 1,714,012

' PIEZO ELECTRIC OSCILLATOR Original Filed April 15, 1926 Inventor: Alexander J.R. T ie o, by His Attorney.

Patented May 21, 1929.

UNITED STATES PATENT OFFICE.

ALEXANDER J. B. FIEGO, OF LYNN, MASSACI IU SETTS, ASSIGNOB GENERAL ELEC- TRIO COMPANY, A CORPORATION OI NEW YORK.

IMO-ELECTRIC OSCILLATOR.

Application filed April 15, 1926,- Serlal No. 102,342, Renewed Ootolier 8, 1928.

Y My invention relates to oscillators compris assembly and accurate adjustment of the oscillator parts. Further objects are the provision of a mounting which permits the electrodes of the oscillator to be readily locked together when the spacing between them has been adjusted.

The embodiment of my invention disclosed in this application is also disclosed together with a difierent embodiment in the co-pending application of Alvarado L. R. Ellis, Serial No. 108,367, filed May 11, 1926, and assigned to the same assignee as the present application. The broad claims to the invention common to both applications are presented in the Ellis application since Ellis is the prior inventor and my invention constitutes an improvement on the invention of Ellis although my application has a filing date in the Patent Office nearly a month earlier than the filing date of the Ellis application.

It is well known that a piezo-electric element, such as a crystal of quartz, or the like,

' will osciilateat a frequency dependent on its dimensions when subjected to an'electrostatic field and that this characteristic of the piezoelectric element may be utilized to predetermine veryaccurately the frequency at which currentis supplied from a source to an output circuit. in order to ensure the best operation of the piezo-electric oscillator, it is desirable that the surfaces of the electrodes and the active surfaces ofthe piezo-electric element be maintained substantially parallel, that the electrode surfaces be accurately spaced from one another, and that means he provided for preventing change in this spacing when it is once adjusted. In accordance with my invention, theseand other usefulresults are secured by a construction wherein the spacing between the electrodes is readily adjusted and wherein the electrodes are selator constructed in accordance with my invention; and Figs. 3 and 4 relate to means for adjusting the electrode spacing and locking the electrodes together when the spacing between them has been adjusted.

Figs. 1 to 4 show electrodes 1 and 2 which are mounted on an insulation base 3, are connected to the plug terminals: 4 and 5 respectively and are surrounded by an insulation cover 6 which is removably attached to the insulation base 3, and is provided for protec ing the electrodes against temperature changes. It should be noted that the electrode 2 is attached to the insulation base 3 by means of screws 7, that the adjustable electrode 1 is threaded into a support member orv resilient collar 8 which. is attached to the insulation base 3 by means of screws 9, that the insulation cover 6 is attached to the base 3 by means of screws 10, and that an insulation cylinder 11 ismounte'd within the support or wall member 8 for insulating this member from a piezo-electrio element which is normally supported between the electrodes 1 and 2. j

The manner in which the electrode .1 is

locked in any position to which it has been adjus'ted will be readily understood upon consideration of Figs. 3 and 4. As indicated by after deformed at points 12, 13 and 14 so that the adjustable electrode 1 will not quite thread into it. In order to permit adjustment of the electrode 1 along the threaded part of wall member 8,4111 adjustment ring 15 is provided. This ring is provided with projections 17 and 18 at its inner periphery and with a thumb-screw 19 which is spaced from these projections and extend through the inner periphery of the ring. a

When it is desired to adjust the electrode 1, the adjustment ring 15 is so positioned around the deformed wall member 8 that the points of greatest deformation toward thecenter of the ring are between the projections 17 t and 18 and between these projections and the thumb-screw 19. The thumb-screw 19is then tightened against the outer wall of the member 8, thus springing the resilient collar memher 8 into a substantially circular form and permitting ready adjustment of the electrode 1/ Upon removal of the adjustment ring the wall member 12 springs back into its normal shape and tightly binds the electrode 1 at the with the adjustment.

that it makes it impossible for any one who is unfamiliar with the construction to tamper- The insulation casing 6 not only protects the oscillator from dirt and moisture, but also prevents change in the spacing between the electrodes due to sudden changes in temperature.

' The embodiment of the invention illustrated and described herein has been selected trodes with any desired spacing therebetween.

for the purpose of clearly setting forth the principles involved. It willbe apparent, however, that the invention is susceptible of being modified to meet the different conditions encountered in its use and I therefore aim to cover by the appended claims all modifications within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. Apiezo-electric device comprising a pair. -of electrodes electrically insulated and mechanically spaced from one another, means comprising a circular collar into which one of said electrodes is threaded for adjusting the spacing between-said electrodes, said collar being deformed at one end to lock said elec- 2. A piezo-electric device comprising a pair I of electrodes electrically insulated and me chanically spaced from one another, a support attached to one of said electrodes, and a mechanical connection between said support and the other of said electrodes for adjusting the spacing between said electrodes, said connection being formed to lock said electrodes with any desired spacing therebetween.

3. A piezo-electric device comprising a pair of electrodes electrically insulated and mechanically spaced from one another, a support attached to one-of said electrodes, and a threaded connection between said support and the other of said electrodes for adjusting the spacing between said electrodes, a part of said connection being of such a form that said electrodes are locked with any desired spacing therebetween.

4. The method of adjusting and maintaining the spacing between a pair of electrodes mechanically interconnected through a connection comprising a resilient collar formed to prevent relative movement between said electrodes, which comprises applying to said collar a force whereby it is sprung into a shape which ,permits relative movement between said electrodes, moving one of said electrodes relatively to the other, and removing said force to prevent further relative movement between said electrodes.

In witness whereof, I have hereunto set my hand this 13th day of April, 1926.

ALEXANDER J. R. FIEGO. 

